This Robot can be used to raise money for the Salvation Army as an autonomous bell ringer. Unfortunately I ran out of time to have him actually go out and fundraise this year. I hope that next year everyone will build one of these and we will have an army of NXT robots ringing bells to help the folks at the Salvation Army. The Bot uses the ultrasonic sensors to see is someone is approaching. The bot then rings the bell by moving its right arm back and forth. (Sorry Lego didn’t make a real bell) If a donation is made the robot will overwhelm you with holiday cheer by playing Jingle Bells on its internal speaker, raising its left arm and waving.